zrchris
GT Owner
In the interest of trying to understand what happened, as some others have asked what mods do you have? Has the SC or accessory belt ever been replaced with one that was perhaps too short? Is your balancer stock or the oversized IW? Does it look okay? Did you notice any shaking or vibrations when the engine was running?
As far as what you should do next, I believe Heffner has said that even for Ray's car they probably did more than they needed to. If you are planning a "regular" Heffner TT, a stock short block is plenty fine. Besides, to go higher you'll need a different fuel system and all sorts of custom things. The 4.0 already pushes the stock fuel limit, but the internals are just fine. Ed found with ported heads etc he could get the same power with less boost, but your problem is the bottom, if it were me I wouldn't turn this into a bigger deal than it is. But keep in mind you could have something out of balance if you can't attribute the problem to something else. You might even want to consider the flywheel or clutch.
As far as what you should do next, I believe Heffner has said that even for Ray's car they probably did more than they needed to. If you are planning a "regular" Heffner TT, a stock short block is plenty fine. Besides, to go higher you'll need a different fuel system and all sorts of custom things. The 4.0 already pushes the stock fuel limit, but the internals are just fine. Ed found with ported heads etc he could get the same power with less boost, but your problem is the bottom, if it were me I wouldn't turn this into a bigger deal than it is. But keep in mind you could have something out of balance if you can't attribute the problem to something else. You might even want to consider the flywheel or clutch.
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